The present invention relates to a connecting rod for an internal combustion engine, having a small connecting rod eye for accommodating a piston pin, and a large connecting rod eye for accommodating a crank journal, whereby at least one connecting rod eye has at least one geometric deviation from a cylindrical inside contour. The present invention furthermore relates to a method for the production of such a connecting rod.
The connecting rod connects the piston of an internal combustion engine with the crankshaft. In this connection, the small connecting rod eye accommodates the piston pin, while the large connecting rod eye surrounds a crank journal. The small and the large connecting rod eye are provided with slide bearing surfaces, for example in the form of slide bearing layers. The slide bearing surfaces of these components are subject to very great mechanical stress. In particular, the piston pin can bend as a result of the tremendous forces that act on the piston during the oscillating movement of the piston. As a result, the connecting pin eyes are subject to great stress. Therefore, ways are being sought to relieve stress on the connecting rod eyes. This is done, for example, by means of local geometric changes in the usually cylindrical connecting rod eye, which reduce the mechanical stress. Such geometric changes can be, for example, stress relief pockets, oval, conical or spherical bores. This principle is already known for pin boss bores, see, for example, WO 96/07841 A1. Such geometric changes have been produced by means of complicated precision machining of the connecting rod eyes until now.
Connecting rods having connecting rod eyes with slide bearing surfaces are known from the German patent application 10 2004 059 490.2. The slide bearing surfaces are coated with a self-lubricating coating made of a resin with solid lubricant particles embedded in it.